This invention relates to novel 2H-benzothieno[3,2-c]pyrazol-3-amine derivatives, to therapeutically acceptable acid addition salts thereof, to processes for their preparation, to methods of using the derivatives, and to pharmaceutical compositions of the derivatives. These derivatives are useful for producing analgesia in a mammal without objectionable side effects of the narcotic analgesic agents. Furthermore, the derivatives produce useful analgesia at doses, which do neither exhibit antiinflammatory nor paralytic effects. In addition, some of the derivatives are useful for inhibiting convulsions, anxiety and aggression, for producing muscle relaxation, and hypnosis, and for inhibiting gastric acid secretion in a mammal.
A number of benzothieno[3,2-c]pyrazole derivatives are known and described, for example, W. J. Barry et al., J. Chem. Soc., 4974 (1956); S. B. Awad et al., Aust. J. Chem., 28, 601 (1975); K. E. Chippendale et al., J. Chem. Soc., Perkin Trans. I, 129 (1973); and F. Sauter et al., Monatsh. Chem., 105, 869 (1974). The compounds reported in the above references lack the substituents on the benzothieno[3,2-c]pyrazole ring system which are characteristic of the compounds of this invention.
A number of 1H-benzothieno[3,2-c]pyrazol-3-amines are disclosed by H. E. Hoffmann et al., U.S. Pat. No. 4,140,785, issued Feb. 20, 1979. The latter amines are readily differentiated from the compounds of this invention by having a methyl or ethyl group at position 1 of the ring system and by having as their sole use chemical intermediates for preparing compounds useful in the treatment of diseases caused by rhinoviruses.